The present invention relates to a display unit and a display control unit for a construction machine, each of which is provided in a cab of the construction machine and displays positional information of a front attachment, such as a bucket end position.
A hydraulic excavator is known as a typical example of construction machines. In the hydraulic excavator, an operator operates front members such as a boom, i.e., constituent members of a front attachment, with corresponding manual control levers. However, it is difficult for the operator to determine whether a trench with a predetermined depth or the face of a slope with a predetermined gradient is precisely excavated, only by visually observing the operation of the front attachment.
FIG. 12 in Specification of U.S. Pat. No. 5,887,365 shows a monitoring unit, i.e., EX-200X Level Master made by Hitachi Construction Machinery Co., Ltd., which is a unit provided in a hydraulic excavator for displaying positional information of a bucket as a working device located at a fore end of a front attachment and for setting a preset target excavation plane when a bucket position is controlled so as not to protrude out of the preset target excavation plane. Such a monitoring unit displays just numerically the positional information of the bucket and setting information of the target excavation plane.
Also, a display unit disclosed in JP,A 10-103925 is known as a unit for entering setting values of depth and gradient for automatic control of a front attachment, and displaying a target excavation plane based on the setting values and the bucket position. The disclosed display unit is able to represent four kinds of setup screens for numerically displaying setting information of the target excavation plane, etc. corresponding to four kinds of control modes, and allows for an operator to set the target excavation plane using the setup screens. When a separately provided trigger switch is depressed in each of the setup screens, automatic control is started and the setup screen is changed to an under-control screen on which the bucket, the target excavation plane, etc. are displayed in the form of symbolic illustrations. Further, the display unit is constructed in the form of a touch panel, and the operator depresses the touch panel to change the setup screen from one to another and to enter numerical values on each of the setup screens.
The monitoring unit described in U.S. Pat. No. 5,887,365 displays numerically the positional information of the working device located at the fore end of the front attachment and the setting information of the target excavation plane. This gives rise to a problem that it is difficult for the operator to visually recognize the position of the working device located at the fore end of the front attachment and the setting state of the target excavation plane with the aid of display of the numerical values only.
The display unit disclosed in JP,A 10-103925 also has a similar problem because the setup screens used for setting the target excavation plane, etc. display numerically the setting information.
Further, the disclosed display unit has the following problems because its primary object resides in making setting for automatic control.
1) When automatic control is started, the setup screen is changed to the under-control screen on which the bucket, the target excavation plane, etc. are displayed in the form of symbolic illustrations. However, the display unit lacks flexibility in selection of the displayed contents. Once the under-control screen is displayed, a shift to another screen is not allowed until the relevant control comes to an end. Accordingly, the operator cannot see the positional information, such as the body tilt angle and the bucket end height, during the automatic control.
2) During a period in which the automatic control is not performed, the setup screen is only displayed. Therefore, the operator cannot see the attitude of the body and the bucket or the target excavation plane during the period not under control.
3) Entry of numerical values for the automatic control is made using the touch panel of the display unit. The site where hydraulic excavators are working, however, undergoes severe environmental conditions in points of, e.g., dust and temperature. Further, the operator often depresses the touch panel with a glove or the like put on the hand. This gives rise to a problem in operability and durability.
A first object of the present invention is to provide a display unit and a display control unit for a construction machine, which allow for an operator to easily set a target plane or area in works to be performed under automatic control, and to freely change the contents to be displayed regardless of whether the machine is under the automatic control, so that information which the operator wants to see can be promptly displayed.
A second object of the present invention is to provide a display unit for a construction machine, which is superior in operability and durability in addition to the above advantages.
(1) To achieve the above first object, the present invention provides a display unit for a construction machine, the display unit being provided in a cab of the construction machine including a front attachment, and comprising a display portion for displaying positional information of the front attachment and setting information for automatic control of the front attachment, and an operating portion for instructing change of contents displayed on the display portion, thereby controlling the displayed contents in accordance with an instruction from the operating portion, wherein the display portion is capable of selectively displaying a first screen for displaying the setting state of a target plane or area in works to be performed under automatic control by using numerical values and a movable symbolic illustration, and at least one second screen for providing another display, each of the first and second screens having a menu area used for changing the first and second screens from one to the other in accordance with an instruction from the operating portion.
Since the display portion is capable of selectively displaying the first screen for displaying the setting state of the target plane or area in works by using numerical values and a movable symbolic illustration, and at least one second screen for providing another display, various settings for the automatic control can be made by displaying the first screen. Also, since each of the first and second screens has a menu area for screen change, a screen image can be changed from the first screen to the second screen or vice versa by instructing screen change with manipulation made on the operating portion. Therefore, the screen image can be changed to the second screen even under control so that the operator can confirm positional information of the body, etc., and the screen image can be changed to the first screen even under not control so that the operator can set the automatic control or confirm the setting state. Thus, the contents to be displayed can be freely changed regardless of whether the machine is under the automatic control, and the information that the operator wants to see can be promptly displayed. Hence, an improvement of the work efficiency is expected.
(2) To achieve the second object, in the present invention according to above (1), the operating portion includes selection keys, numerical value entry keys, and a decision key; the first screen changes display of the setting state upon manipulation of the numerical value entry keys; and the menu area in each of the first and second screens is used for changing the first and second screens from one to the other with manipulation of the selection keys and the decision key.
With those features, the display portion is no longer required to use a touch panel, and operability and durability of the display unit can be improved even in any site where construction machines are working.
(3) In above (1), preferably, when the automatic control is started, each of the first and second screens displays that the construction machine is under control.
With that feature, even when the screen image on the display portion is changed to any screen, the operator is able to know that the machine is currently under the automatic control, and hence to perform works without anxiety.
(4) In above (1), preferably, the second screen includes a screen for displaying, in enlarged scale, the positional relationship of a fore end of the front attachment relative to the target plane or area in the works by using a movable symbolic illustration.
With that feature, when works are performed in a location where the operator cannot visually confirm the position of the bucket fore end, the operator is able to perform the works while always confirming the position of the bucket fore end and the position of the target plane or area in the works by looking at the second screen. The excavation monitoring screen is effective. Further, since the screen image can be changed to the second screen even when the automatic control is turned OFF, excavation works to obtain the target plane or area can be performed with the operator""s operation while looking at the second screen.
(5) In above (1), preferably, the menu area has a plurality of items including an item of screen change; the operating portion includes first entry means for selecting a desired one of the plurality of items in the menu area, and second entry means for deciding the selection made by the first entry means; and the display portion changes the first and second screens from one to the other when the item of screen change is selected by the first entry means and the selection of the item of screen change is decided by the second entry means.
With those features, the first and second screens can be changed from one to the other using the operating portion (first and second entry means) and the menu area.
(6) In above (1), preferably, the menu area of the first screen has an item of screen change and an item of automatic control ON/OFF; and the display portion changes the first and second screens from one to the other regardless of the selected state of the item of automatic control ON/OFF when selection of the item of screen change is instructed from the operating portion.
With those features, the first and second screens can be freely changed from one to the other with the aid of the menu area regardless of whether the machine is under the automatic control.
(7) In above (1), preferably, the menu area of the first screen has a plurality of items including an item of screen change and an item of automatic control ON/OFF; the menu area of the second screen has a plurality of items including an item of screen change; the operating portion includes first entry means for selecting a desired one of the plurality of items in the menu area, and second entry means for deciding the selection made by the first entry means; and when one item is selected by the first entry means and the selection of the one item is decided by the second entry means, the display portion executes the selected item.
With those features, the first and second screens can be freely changed from one to the other with the aid of the menu area upon manipulation of the first and second entry means regardless of whether the machine is under the automatic control.
(8) Also, to achieve the above first object, the present invention provides a display unit for a construction machine, the display unit being provided in a cab of the construction machine including a front attachment, and comprising a display portion for displaying positional information of the front attachment and setting information for automatic control of the front attachment, and an operating portion for instructing change of contents displayed on the display portion, thereby controlling the displayed contents in accordance with an instruction from the operating portion, wherein the display portion is capable of selectively displaying a first screen for displaying the setting state of a target plane or area in works to be performed under automatic control by using numerical values and a movable symbolic illustration, a second screen for displaying sates of a body of the construction machine and the front attachment by using numerical values and a movable symbolic illustration, and a third screen for displaying, in enlarged scale, the positional relationship of a fore end of the front attachment relative to the target plane or area in the works by using a movable symbolic illustration, each of the first, second and third screens having a menu area used for changing the first, second and third screens from one to another in accordance with an instruction from the operating portion.
With those features, as described in above (1), the target plane or area in the works to be performed under the automatic control can be easily set, and the contents to be displayed can be freely changed regardless of whether the machine is under the automatic control. Hence, information that the operator wants to see can be promptly displayed, and the work efficiency can be improved.
(9) Further, to achieve the above first object, the present invention provides a display control unit for a construction machine, the display control unit being provided in a cab of the construction machine including a front attachment and controlling, in accordance with an instruction from an operating portion, contents displayed on a display portion for displaying positional information of the front attachment and setting information for automatic control of the front attachment, the display control unit comprising first control means for causing the display portion to selectively display a first screen for displaying the setting state of a target plane or area in works to be performed under automatic control by using numerical values and a movable symbolic illustration, and at least one second screen for providing another display, and to display a menu area including an item of screen change in each of the first and second screens; and second control means for processing the item of screen change in accordance with an instruction from the operating portion and changing the first and second screens from one to the other.
With those features, as described in above (1), the target plane or area in the works to be performed under the automatic control can be easily set, and the contents to be displayed can be freely changed regardless of whether the machine is under the automatic control. Hence, information that the operator wants to see can be promptly displayed, and the work efficiency can be improved.